Apparatus for making artificial stone.



F. R. STEHM. APPARATUS FOR MAKING ARTIFICIAL STONE. APPLICATION FILED MAY14,1906. RENEWED MAY 6,1914.

1 101 5780 Patented. June 30, 19141:.

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F. R. STEHM. APPARATUS FOR MAKING ARTIFICIAL STONE.

AY l), 190. RENEWED MAY 6,1914 LIULWYI Patented June 30,1914.

5 SHEETS-*SHBET ZI APPLICATION FILED M F. R. STEHM. APPARATUS FOR MAKING ARTIFICIAL STONE. APPLICATION FILED MAY 14, 1906. RENEWED MAY @1914.

L10L57 Patented June 30,1914.

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Ziivmwax P. R. STEHM. APPARATUS FOR MAKING ARTIFICIAL STONE. APPLICATION FILED MAY 14. 1906. RENEWED M Patented June 30, 1914;.

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F. R. STEHM. APPARATUS FOR MAKING ARTIFICIAL STONE. APPLICATION FILED MAY 14,1906 RENEWED MAY 6,1914.

Patented June 30, 1914.

STATES FATE FRANK B. STEHM, OF DES MOINES, IOWA, ASSIGNOR, BY DIRECT AND AND MACHINERY COMPANY,

IOWA, A CORPORATION OF SOUTH DAKOTA.

MENTS, TO THE ENAMEL CONCRETE MESNE ASSIGN- or nus MOINES,

APPARATUS FOR MAKING ARTIFICIAL STONE.

Specification of Letters Patent.

Patented June 311), 11914.

Application filed May 14, 1906, Serial No. 316,893. Renewed Kay 6, 1914. Serial No. 836,808.

To all whom it may concern:

1: it known that I, FRANK R. S'rmnr, a oitizenof the United States, residing at Des Moines, in the county of Polk and State of Iowa, have invented a certain new and useful Apparatus for Making Artificial Stone, of which the following is a specification.

The object of my invention is to provide an apparatus of simple and durable construction for manufacturing artificial stones quickly and easily and in large numbers, which stones when finished will have one or more surfaces smooth and glossy and the corners adjacent to said surfaces smooth and slightly rounded and said surfaces hard and highly impervious to moisture.

My invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are retained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings, in which Figure 1 shows a side elevation of the complete apparatus to illustrate the general arrangement of the several parts thereof. Fig. 2 shows a side elevation of the first compressing device with a mold in position thereon, parts of which are broken away to show the presser plates within the mold. Fig. 3 shows a top view of one of the molds. Fig. 1 shows an end elevation of the presser device shown in Fig. 1. Fig. 5 shows a detail, perspective view of the removable partitions for the mold and the device for connecting and supporting them. Fig. 6 shows a detail, perspective view of one of the surfacing plates. Fig. 7 shows a top or plan view of the presscr plates of the first pressing device, to illustrate the means for adjustahly connecting and supporting them. Fig, 8 sll()\\'S a sectional view on the line S 8 of Fig. (3. Fig, 9 shows an end elevation, partly in section, of one of the molds with the detachable partition therein. Fig. 10 shows a side "iew of the final pressing device of the apparatus with a mold therein having a part broken. away to show the pre ser plates and the guides within the mold, and Fig. 11 shows an edge view of the sa me device with parts broken away to show certain details of construction.

Referring to Fig. 1 of'the drawings, the apparatus is seen to groove 22.

be composed of three independent pressing devices arranged in line and connected by a conveyer, which conveyor comprises two angle bars 10 with a sprocket chain 11 traveling upon each end, provided with uprights 12 projecting above the angle bars. These angle bars extend through all of the pressing devices and beyond the first and last pressing device of the apparatus. Any suitable means may be provided for advancing the chains of the conveyer.

The first pressing device, which is illustrated in Figs. 2 and 4, comprises a supporting frame 13 having a top 14 on which the angle bars 10 are mounted. Erected above the top 14 is a supplemental frame 15 having at its top the rock shaft 16. On one end of this rock shaft 16 is a pulley 17 formed with a clutch member 18, said pulley being rotatably mounted on the shaft. Adjacent to the clutch member 18 is a mating clutch member 19, slidingly and non-rotatably mounted on the shaft and normally held, by a spring 20, in engagement with the clutch member 18. Formed on the central portion of the clutch member 19 is a number of spirally arranged ribs 21 and an annular 'Fulcrumed to the auxiliary frame 15 is a lever 23, beneath said clutch, this lever is provided with a projecting end designed to enter the annular groove 22 or to engage the spiral ribs 21, said lever is controlled by a rod 24 pivoted to it and to a foot treadle 25, which is normally elevated by a spring 26. In use with this portion of the device, the pulley 17 is normally rotated and the shaft 16 is stationary. By depressing the trea dle 25, the operator withdraws the lever 23 from the clutch member 19 and the spring 20 forces the clutch members into engagement. Then the operator removes his foot from the treadle and the lever 23 is elevated so that its end strikes one of the spiral ribs 21 and in this Way forces the clutch member away from the clutch member 18 until the lever 23 enters the annular groove 22 and then the clutch members are held separated. ()n the other end of shaft 16 is a crank arm 27 to which a contractible coil spring 28 is fixed to normally hold said rock shaft 16 at a certain limit of its movement whenever the clutch members 18 and 19 are released. Fixed to the shaft 16 on opposite sides of its center downwardly are two crank arms 29, each having pivoted at its lower end a rod 30. These rods 30 are made adjustable as to length by means of the adjusting nuts 31 and their lower ends are pivoted to the cross piece 32 of the presser plates, hereinafter described, by the pins 33. This cross piece 32 is provided with lugs 23% at its sides and with the longitudinal slots 35. near its edges. A number of presser plates 36 are connected with this cross piece 32 by means of bolts 37 passed through the slots 35 and into the presscr plates. In this way the plates may be adjustably secured to the cross bar 32. I have provided for guiding the cross bar in its up and down movement as follows: Two guide bars 38 have their lower ends passed through the lugs 34 and their central portions passed through a cross piece 3!) supported by the frame 15 and their tops passed through the cross piece 40 supported by the frame 15. By this arrangement, it is obvious that, when the shaft 16 is rocked in one direction, all of the presser plates will be jointly moved and when the rock shaft is returned to its normal position by its spring, the presser. plates will be jointly elevated.

I have also provided means for accurately centering a mold with relation to the presscr plates as follows: l' ulcrumed to one side of the frame 15 is a lever a1 and fulcrumed to the opposite side of the frame is a lever 12 which lovers are pivotally connected by a'link 43. Pivoted to each of said levers is acentering bar 41-4 formed with slots 45, each of said bars is mounted in a guide 46 and the pins 47 are fixed to said guide and passed through the slots 4-5. By this arrangement, the operator may grasp the lever 41 and move its top inwardly toward the frame 15, whereupon both of the centering liars -14: will be moved inwardly to engage a mold and center it accurately beneath the presser plates.

The second pressing device of the apparatus is constructed sul'istantially like the one just described and is provided for the purpose of permitting an operator to partially fill the mold cavities of one mold during'the same time that another operator is performing the same operation for the first pressing device, as will hereinafter more fully appear.

After the molds have passed through the second pressing device, it is desirable to remove the molds from the finished artificial stone. The device that I have provided for this purpose is illustrated in Figs. 10 and 11 and comprises a main frame 48 having a cross piece 49 upon which the angle bars 10 of the conveyor are supported. Adjacent to the'outcr face of each of said angle bars is a roller 50 supported in the brackets 51 and arranged parallel with the angle bars with their tops slightly above the angle 'tering of the molds bars. Mounted in the top of the frame 48 is a rock shaft 52 having a lever 53 fixed thereto by which the shaft may be manually rocked, and on one end of the shaft is a crank arm 54 to which a contractible coil spring 55 is attached, the other end of the spring being connected with the frame, said spring normally holding the shaft 52 in position with the lever 53 elevated. Fixed to said shaft 52 are two crank arms 56 to which the rods 57 are pivoted. The lower ends of these rods 57 are pivoted to the cross piece 59 of the presser plates. Means are provided for guiding this cross piece and the presser plates in a straight line vertically as follows: F ixed to the ends of the cross piece 59 are the guide rods (30 passed through the guide brackets 61 and the top plate 62. Attached to the cross piece 5.) is a series of presser plates (53 having c0mparatively long uprights to the cross piece 59. At the center of the cross piece 59 are two guide bars 65 with their lower ends beveled downwardly and toward each other, said guide bars being de signed to enter an opening provided for them in each mold for the purpose of centering the mold accurately under the presser plates. to, are for the purpose of permitting the mold to move longitudinally in a direction transversely of the frame 48 so that this cenmay be easily accomplished by said centering bars. The lower ends of said centering bars project below the presser plates so that they alone first strike the molds when the presser plates descend.

I have provided means for elevating the molds while the presser plates still remain in contact with the material in the molds as follows: Mounted near the top of the frame 48 is a rock shaft (36 having attached at one end a hand lever 67 and to the other end a pinion 68. Adjacent to the shaft 66 is a similar shaft (39 provided with apinion 70 in mesh with the pinion 68. Fixed to each shaft 66 and 6!) are two crank arms 71, each of which has connected to it a. rod 72. Each bar of the rods 72 is connected to a vertically slidable frame 73 mounted in the guides 74 and at the lower end of each side of the frame 73 is an angle. bar 75 arranged with its lower portion projected inwardly under a mold'in the frame 48, as will hereinafter more fully appear. In use with this portion of the device and assuming a mold to be in a position with the angle bars 75 under the edges thereof and the presser plates elevated, then the operator first ma nipulates the lever 53, which forces the presser plates downwardly into engagement with the material in the mold cavities. This holds said' material firmly against the off-bearing plate upon which the mold rests, then the operator manipulates the lever 67,

64, which are attached The rollers 50, previously referred which elevates the mold to a point above the material resting onthe off-bearing plate and finally the lever is released and the sprin elevates the presser plates so that the bearing plate containing the artificial stones may he moved away from the frame 48 by the conveyor.

For each mold, I have provided an oil'- hearing plate 76 having a raised central portion 77, said plate being of a width to extend over the tops of the two angle bars and designed to be engaged by the uprights 12 on the conveyer chains 11. Each mold comprises two side pieces 78 and two end pieces 79 and anumber of transverse partitions 80, the parts being held together by bolts 81. The two central partitions 80 are designed to coact with the guide bars for the purpose of centering the mold beneath the presser plates of the last device for pressing the material in the mold and for removing the mold from the material. The length of the side pieces 78 of each mold is such that the ends will project beyond the raised central portion of the off-bearing plate and where they may be engaged by the angle bars 7 5. For each mold cavity of the mold, I have provided a surfacing plate, preferably made of a single piece of thin spring metal and comprising a bottom 82 with upturned side margins 83 and an upturned end margin 84. At the opposite end of the plate is an end piece 85 formed integral with the bottom piece and having a smooth, slightly rounded corner at 86. The side margins of the part 85 are inclined inwardly at 87. The inner face of this surfacing plate is formed smooth. non-erosive, moisture-repellent and non-adhesive. This ma be done by providing it with a coating of 1apan, thoroughly baked or in any other suitable way. Said surfacing plates are of such size that they may be placed in the mold cavities with their margins flush with the inner walls of the mold cavities.

I have also provided detachable partitions for the mold cavities as follows: 88 indicates a cross piece having the arms 89 fixed to its ends and a series of thin spring metal partitions 9O fixed to it. In use the cross piece is placed on top of the mold and the arms 8!.) are placed against the projecting ends of the adjacent side plate 78 of the mold, thus causing the partitions 90 to stand adjacent to the inner face of the mold cavity in which the end 85 of the surfacing plate is located with the bottoms of said partitions slightly spaced apart from the bottom of the surfacing plate, said partitions normally standing with their tops nearer the end 85 than their lower ends. a

In practical operation, an off-hearing plate is placed upon the angle bars of the conveyor and a mold plac'edthereon. Then a surfacing plate is placed in each mold 't-ion for forcmg cavity with the bottom of the surfacing plate forming the bottom of the mold and resting on the oifbearing plate. I then place upon each mold a cross piece containing partitions for each mold cavity. I then place in each surfacing plate a small quantity of cement so diluted with liquid that it will readily flow over the surface of the surfacing plate. The quantity of material first placed upon the surfacing plates is such that it will be contained wholly within the upturned margins of said surfacing plates and, therefore, will not overflow upon the off-bearing plate. I then place in each mold cavity aquantity of stone making material in moist condition. This material may be composed of cement and sand with enough water added to moisten it and yet not enough to thoroughly saturate it. By placing this material on top of the material in liquid form first inserted, the material in liquid form is forced by the weight of the other material upwardly between the space formed by the partitions and the upturned ends of the surfacing plates. The partitions prevent any of the material from entering on the top ofthc space between the partition and the end of the finishing plate. Then theconveyer isadvanced until the mold is directly under the first pressing de vice. Then the operator presses upon the treadle 25, which sets the machinery in mothe presser plates downwardly into the mold cavity and firmly compresses the material therein. This pressure will cause part of the liquid surfacing material to flow into and fill the spaces between the partitions and the ends of the surfacing plates, and it will also force out the air from between the surfacing plates and the material so that a smooth unbroken contact will be had. During the time that the presser plates are moving downwardly in the mold cavities, they will engage the partitions and cause the lower ends thereof to "spring toward the ends of the surfacing plates and this movement will also aid in forcing the liquid material upwardly in the spaces between the partitions and the ends of the surfacing plates. T hen. the conveyor is again advanced and the mold is again filled with stone making material in moist condition, which may comprise cement and sand with enough liquid added to moisten the mass. Then the cross piece bearing the partitions is removed and the mold advanced by the conveyer to position directly over the second pressing device. Then the machinery for lowering the presser plates is set in motion and the final compression of the material is made by the resser plates. Then the mold is advanced to the device for separating the molds from the surfacing plates and finished stones and the operator first moves theresser plates downwardly into firm contact with the finished stones and then manipulates the lever for raising the mold. Then the off-bearing plate with the surfacing plates and stones is advanced by the conveyor and carried away to be dried.

lt is of great importance in an apparatus of this kind that the surfacing plates are not shaken or jarred loose at any point from the stones. By my improved apparatus the material is molded upon the surfacing plates While they rest upon the off-bearing plateand it is not necessary for the operator to touch either the stones or the surfacing plates until after the stones have thoroughly dried and hardened. By removing the mold from the stones, the sides and tops of the stones will be exposed to the air so that they will dry first While the drying and crystallizing and hardening process on the surfaces of the stones adjacent to the surfacing plates will be slower and I have found that this tends to permit these surfaces of the stones to thoroughly crystallize and present a smooth and glossy appearance free from pores or interstices that might tend to absorb moisture. lly having the surfaces of the surfacing plates made smooth, nonabsorbent and moisture-repcllcnt, l have found that if the stones have dried and bardened in unbroken contact. with said surfaces, the stoncs will be smoothand crystallized and present a glossy appearance and after such hardening and crystallization, the surfacing plates may be removed and when so removed will be perfectly clean and free from any of the material of which the stones were formed. By having said surfacing plates made non-erosive they will remain in their smooth, clean and moisture-repellent condition after repeated use. By having the surfacing plates formed with a bottom and a side member made of one piece, there will be no cracks or rough surfaces at the corners of the finished stone, such as would be caused if two independent plates were used for this purpose. By having the margins of the surfacing plates projected upwardly, as shown, the liquid material. first. introduced is retained wholly within said surfacing plates and hence the finished stone will present. smooth, slightly rounded corners and will not be rough and uneven as would be the case if the top of the surface. plate were flat.

Having thus described my invention, what I claim and desire to secure by Letters Patent of the United States, therefore is- 1. In an apparatus of the class dcscribctha frame, a mold support thereon, two sliding bars on opposite sides of the frame above through the frame to support a mold, a convcycr formed with fingers projecting upwardly above the bars to move a mold over the bars and through the frame and means for engaging the sides of the mold and a.ccu rately centering it within the frame.

3. In an apparatus of the class described, the combination of a frame, a mold support thereon, a series of connected presser plates above the'mold support, a rotatable shaft, crank arms on the shaft, rods connecting the crank arms with the presser plates, a pulley rotatably mounted on the crank shaft and having a clutch member, a sliding non-rotatable clutch member on the shaft, means for moving said clutches into or out of engagement with each other and spring-actuated means for automatically elevating the presser plates when the clutch members are released.

4. In an apparatus of the class described,

the combination of a frame, a mold support thereon, a series of connected presser plates above the mold support, a rotatable shaft, crank arms on the shaft, rods connecting the crank arms with the prcsser plates, a pulley rot atably mounted on the cran k shaft; and having a clutch member, a sliding non-rotatable clutch member on the shaft, manuallyrcleased spring-actuated means for throwing the sliding clutch member into engagement with the rotary clutch member and springactuated means for automatically elevating the presser plates When the clutch members are released.

5. In an apparatus of the class described, the combination of a frame, a mold support thereon, aseries of connected presser plates above the mold support, a rotatable shaft, crank arms on the shaft, rods connecting the crank arms with the presser plates, a pulley rotatably mounted on the crank shaft and having a clutch member, a sliding non-rotatable clutch member on the shaft, manually-released, spring-actuated means for throwing the sliding clutch member into engagement with the rotary clutch member, means for automatically throwing the sliding (ZllllLCllJlKlHlNl out of engagement with the rotary clutch member and, spring-actuated means for automatically elevating the presscr plates when the clutch members are releasedl 6. In an apparatus of the class described, the combination of a frame, a mold support thereon, a rock shaft mounted in the frame, crank arms on the shaft, a prcsser plate, rods connecting the crank arms and presser plate, a rotatable pulley on the rock shaft formed with a clutch member, a slidthe mold support and manually operated ing clutch member on the shaft formed with means for ointly moving them to orfrom an annular groove and with a series of short each other. spiral ribs adjacent to said groove, a spring 2. In an apparatus of the classdescribed,

for forcing the slidingclutch member tothe comblnation of a frame, bars extended Ward the rotatable one, a pivoted arm yieldingly held toward the sliding clutch member and designed to enter the groove there of or to engage the spiral ribs thereof, and means for manually withdrawing said arm from the clutch.

7. In an apparatus of the class described, the combination of a frame, a mold support thereon, a rock shaft mounted in the frame, crank arms on the shaft, a presser plate, rods connecting the crank arms and presser plate, a rotatable pulley on the rock shaft formed with a clutch member, a sliding clutch member on the shaft formed with an annular groove and with a series of short spiral ribs adjacent to said groove, a spring for forcing the sliding clutch member toward the rotatable one, a pivoted arm yieldingly held toward the sliding clutch member and designed to enter the groove thereof or to engage the spiral ribs thereof, means for manually withdrawing said arm from the clutch and a spring tending to rock the shaft in a direction to elevate the presser plate.

8. In an apparatus of the class described, the combination of a frame, mold supporting bars extended through the frame, rollers adjacent to the bars and parallel therewith and having their tops slightly above the bars to engage and support a mold while within the said frame and to permit said mold to move freely in a direction across the tops of the rollers.

9. In an apparatus of the class described, the combination of a frame, mold supporting bars extended through the frame, rollers adjacent to the bars and parallel therewith and having their tops s ightly above the bars to engage and support a mold while within the said frame and to permit said mold to move freely in a direction across the tops of the rollers and a mold centering de vice.

10. In an apparatus of the class described, a surfacing plate made of a single piece of material and comprising a bottom having upturned margins and a side piece having margins projecting inwardly over the upturned bottom.

11. In an apparatus of the combination of a mold the class described, and a detachable swinging partition supported initially in an inclined position near one end of the mold and spaced apart from the bottom of the mold.

12. In an apparatus of the class described, the combination of a mold, a surfacing plate having a bottom and a side resting in the mold and a detachable partition yieldingly supported adjacent to the side of the surfacing plate and spaced apart from the bottom of the surfacing plate.

13. In an apparatus of the class described, the combination of a mold, a cross piece resting on top of the mold, arms on the cross piece to engage a portion on the exterior of the mold to support the cross piece, and a partition fixed to the cross piece to project downwardly into the mold with its lower end spaced apart from the bottom of the mold and movable with a toward an end of the mold.

14. In an apparatus of the class described, the combination of a mold and a yieldingly, detachable partition normally standing with its top near one end of the mold and its body portion extended downwardly and to ward the center of the mold to a point spaced apart from the bottom of the mold and capable of being moved by pressure within the/interior of the mold to a substantially upright position.

15. In an apparatus of the class described, a mold formed of sides and ends with the sides projecting beyond the ends, a detach-- able cross piece on top of the mold, arms extended downwardly and laterally to engage the projecting ends of one side of the mold and a spring metal partition fixed to the cross piece and extended downwardly and toward the center of the mold away from the side of the mold that is engaged by said arms.

16. In an apparatus of the class described, the combination of a frame, a series of presser plates connected with each other and vertically movable within the frame, a pair of centering bars having beveled lower ends connected with the presscr plates, a mold support within the frame, a mold therein having partitions arranged to be engaged by said centering bars when the presser plates are lowered toward the mold.

17. In an apparatus of the class described, the combination of a frame, a series of presser plat-es connected with each other and vertically movable within the frame, a pair of centering bars having beveled lower ends connected with the presser plates, a mold support within the frame, a mold therein having partitions arranged to be engage by said centering bars when the presser plates are lowered toward the mold, said moldsupport including rollers for permitting longitudinal movement of the mold.

18. In an apparatus for making artificial stone comprising a conveyor, for supporting and advancing molds, one or more frames, each having said conveyor passed through it and each having a Presser plate capable of up and down movement to and from the convcyer and a frame also having said conveyor passed through it and a presscr plate capable of up and down movement toward the conveyer and a mold elevating device capable of independent up and down movement.

19. In an apparatus of the class described, the combination of three frames, two angle bars extended lon itudinally through said frame, conveyor c ains supported by the swinging motion angle bars and haviing lingers to project upwardly above them, an olf bearing plate resting on. the angle bars to be engaged by said fingers, an open bottomed mold on top of the off-bearing); plate, a presser plate in the first frame, means for vertically moving it to compress material within the mold, a similar presser plate within the second frame, a similar presser plate within the third fran'ie and means for elevating the moldfrom the off-bearing plate while the presser plate is still in engagement with the material resting on the eff-bearing plate.

20. In an apparatus of the class described, the combination of a mold including the mold sides and a mold body, a flexible surbottom without the stone making material and the surfacing 25 'l'aeing plate (letaehably mounted in the mold and resting upon said bottom, means for applyil'ig pressure to stone making material in the mold surfacing, plate, and means for separating the mold sides from the stone making material and the surfacing plate and the mold breaking contact between plate, and without removing the pressure therefrom.

Des Moines, Iowa, May 5, 1906..

FRAN K R. STEHM. Witness-es J. RALPH ORWIG, S. F. CHRISTY.

to hold it firmly against said 

